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Jan. 1, 1963
P. E. BESSIERE
3,071,074
SELF-REGULATING PIS’I‘ON PUMPS AND IN
PARTICULAR FUEL INJECTION PUMPS
Filed Jan. 26, 1959
2 Sheets-Sheet 1
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NSN
Jan. 1, 1963
3,071,074
P. E. BESSIERE
SELF-REGULATING PISTON PUMPS AND IN
PARTICULAR FUEL INJECTION PUMPS
Filed Jan. 25, 1959
2 Sheets-Sheet 2
l@ s.
ATTUR EYS
United States Patent Oñice
l
ìh'llßld
Patented dan. 1, 1963
2
of the piston are constituted by a spring 6 housed in cham
»
ber 2a.
_in the embodiments illustrated by the drawings, the
3,071,074
SELF-REGULATWG PlSTGN PUMPS AND Esi
PARTICULAR FUEL ENJECTIUN PUMPS
Pierre Etienne Bessiere, 55 Blvd. Commandant Charcot,
Neuilly-snr-Seine, France
Filed Jan. 26, 1959, Ser. No. 738,816
Claims priority, application France Jan. 28, 1958
7 Claims. (Cl. 10S-41)
mechanical means for producing the delivery strokes of
5
the piston include a cam 7 mounted on a shaft S (FIG. 3)
driven at a speed proportional to that of the engine, The
piston carries rigid therewith a push-rod 9 guided in a
cylindrical bore 10 starting from the bottom of chamber
2b and this rod 9 cooperates with a sliding member 11
The present invention relates to self-regulating piston
urged downwardly by a spring 12 and carrying a roller
pumps and in particular fuel injection pumps for internal
13 in contact with the periphery of cam 7. In the arrange
combustion engines (this term designating all kinds of
ment of FIGS. 2 and 3, the push-rod 9, instead of being
engines, including diesel engines). The pumps with
rigid with piston 1 as in FIG. l, is separate therefrom and
which the present invention is concerned include a piston
bears against the under face of said piston. Anyway, the
dividing the cylinder in which it reciprocates into a pres 15 play between push-piece 9 and bore 1|) is suiiiciently
sure chamber and a regulation chamber, this piston being
small (account being taken of the length of bore 10 and
actuated mechanically during its delivery stroke, that is
of the pressure in chamber 2b) to prevent any leakage of
to say in the direction which causes the volume of the
pressure chamber to be reduced, and being moved in the
fluid through this bore.
Of course, the mechanical means above described are
opposed direction, during its return stroke, by suitable 20 given merely by way of example and any other equivalent
resilient means, the pressure chamber being provided with
a feed conduit opening thereinto and with a delivery con
duit for the outflow of the liquid supplied by the pump
and the regulation chamber being provided with a liquid
means may be used for the same purpose. For instance,
sliding member 10 might be replaced by a bent lever piv
oted about an axis located at the level of its bend and
having one of its ends applied against cam 7 and the
inlet conduit and with an outlet conduit including means 25 other against the end of push-rod 9.
Passage 3 is provided in a communication conduit 14
for braking and/ or temporarily stopping the flow of liq~
uid passing therethrough in such manner that, when the
extending from chamber. 2b to chamber 2a and acting as
speed at which the pump is driven exceeds a predeter
fuel feed conduit for said chamber 2a. As for chamber
mined value, every return stroke and consequently the
21„ it is fed with fuel through a conduit 15 provided with
30
next delivery stroke of the piston are shortened and the
a check-valve 16 and connected with a suitable source of
volume of liquid delivered on every cycle of the pump
fuel under pressure such as a low pressure auxiliary pump.
through the delivery conduit decreases.
The diameter of piston 1 being the same at both of
The object of this invention is to provide a pump of
its ends, the volume displaced in chamber 2„ is greater
this kind which is better adapted to meet the require
than that displaced in chamber 2b due to the presence in
ments of practice than those known up to this time.
said last mentioned chamber of push-rod 9 (FIG. l).
The pump according to my invention is characterized
Consequently, whatever be the length of the strokes of
by the fact that the outlet conduit starting from the regu
piston 1, chamber 2„ is always uncompletely ñlled with
lation chamber constitutes the feed conduit leading to the
fuel. In order to remedy this drawback, it is advanta
pressure chamber and is provided with means for pre
geous to provide piston l, on the side opposed to push
venting back flow of liquid from the pressure chamber
rod 9, with an extension 17 (FIGS. 2 and 3) of cylindrical
during the delivery strokes of the piston, the inlet conduit
shape having the same cross section as push-rod 9 and
of the regulation chamber being connected with a source
moving in a housing 13 which preferably opens to the
of the liquid to be delivered by the pump.
outside through an aperture 19. Of course, part 17 is lit
Preferred embodiments of the present invention will be
ted in a housing 18 in such manner as to prevent any out
hereinafter described with reference to the accompanying
ward leakage of iluid from chamber 2a.
drawings, given merely by way of example and in which: 45 ln order to limit the active portion of the delivery
FlGS. 1, 2 and 3 are diagrammatic sectional views of
stroke of piston 1, this piston 1 is provided with a groove
pumps made according to three different embodiments of
21B communicating through a longitudinal conduit 21 with
the invention.
chamber 2,. This groove 20 cooperates with a discharge
The pumps shown by the drawings are fuel injection
50 conduit 22 so as to communicate therewith before piston
pumps to be used for instance in connection with diesel
1 reaches the end of its delivery stroke.
engines.
According to a iirst embodiment of this invention, the
Piston 1 is adapted to reciprocate in a cylinder Z so as
above mentioned passage 3 may be arranged so as to
to divide it into two chambers, respectively a pressure
brake the return movement of piston 1, effected under the
chamber 2a and a regulation chamber 2b. This piston is
action of spring 6, without delaying the beginning of said
subjected on the one hand to the action of mechanical 55 return movement. For this purpose, passage 3 constitutes
means for moving it positively in the direction which re
a throttled section of conduit 14 (FIGS. 1 and 2). As
duces the volume of pressure chamber 2„u (delivery stroke,
in the upward direction) and on the other hand to the
action of return means for moving the piston in the op~
posed direction (return stroke, in the downward direc-»
this throttled passage is permanently open, it is necessary
-to provide means for preventing the back liow of liquid
60 through conduit 14 during the delivery stroke of the pis
ton. Such means are constituted by check-valve 23.
tion) under the effect of suitable resilient means. Dur
As shown by FIGS. l and 2, throttled passage 3 may
be limited by a screw 24 which, in the construction shown
ing its upward stroke, the piston delivers fuel from pres
by the drawings, is adjusted manually. However, this
sure chamber 2,L and, during the return stroke, the piston
drives the liquid present in regulation chamber 2b through 65 screw might be automatically controlled as a function
a passage 3 of relatively small section capable of braking
or delaying the return movement of the piston.
The pressure chamber 2„ is connected with the injec
tor or injectors of the engine to be supplied with fuel by
the pump through a delivery conduit 4 provided with a
check-valve 5. The means producing the return strokes
of the speed of the engine by a suitable governor such as
a centrifugal governor or a hydraulic governor operative
by a pressure varying with the speed of the engine.
The operation of a pump such as shown by FlGS. 1
and 2 is as follows.
Initially piston 1 is in the position shown by the draw
ings. Cam 7 causes piston `1 to move upwardly, through
aprieta
roller t3, sliding member il and push-rod 9. `Piston l
cylinder, said piston dividing said cylinder into two cham
compresses spring d and causes the liquid contained in
chamber 2a to be delivered toward the injector or injectors
bers, respectively a pressure chamber and a regulation
chamber, a shaft, mechanical means driven by 4said shaft
of the engine through conduit 4, past' check-valve 5
(check-Valve 23 being closed by the effect of the pres
sure).
During this time, chamber 2b, the volume of which has
been increasing, is iilled with fuel flowing past check-valve
i6. injection stops when groove Ztl opens discharge con
duit 22 thus causing the pressure in chamber 2„ to drop,
owing to the provision of conduit 2f. Piston il still moves
a short distance in the upward direction, groove Zit re
maining in communication with conduit 22.
Then piston i stops and starts moving downwardly.
At this time, fuel is transferred from chamber Z1, to cham
ber 2„ through conduit 14 which includes the throttle-d
passage 3.
This throttled passage brakes the downward movement
of piston 1 which takes place under the effect of spring
and directly connected with said piston for actuating said
piston under the action of said shaft only in one direction
to produce the delivery strokes of said piston, during
which the volume of said pressure chamber is reduced,
resilient means interposed between said piston and said
cylinder for actuating said piston in the opposed direc
tion independently of the action of said shaft to produce
the return strokes of said piston, during which the volume
of said regulation chamber is reduced, a delivery conduit
leading out from said pressure chamber, a liquid inlet
conduit opening into said regulation chamber, said inlet
conduit being connected with a source of the liquid to
be delivered by the pump, valve means in said inlet con
duit permitting inliow of liquid into said regulation cham
ber only during the delivery strokes of said piston, a feed
conduit starting from said regulation chamber and open
6 at a speed lower than that of sliding member il. This 20 ing into said pressure chamber, means located at least
partly in said feed conduit for delaying the flow of liquid
member, at least for speeds of operation higher than a
therethrough from said regulation chamber to said pres
given value, reaches its lowermost position and starts
sure chamber, and valve means in said feed conduit armoving back upwardly before piston 1 comes into contact
ranged to prevent back flow of liquid through said feed
with its lower abutment. Sliding member 11 therefore
contacts push~rod 9 as it is moving downwardly, which 25 conduit, in the direction leading from said pressure cham
ber to said regulation chamber, during the delivery strokes
stops the transfer of liquid through conduit ld and marks
of said piston.
the beginning of a new injection of fuel.
2. A pump according to claim 1 in which the means
The higher the speed at which the pump is driven, the
for delaying the iiow of liquid through said feed conduit
higher the level at which push-piece 9 is stopped during
its downward stroke by sliding member 11 and the shorter 30 and the means for preventing back flow of liquid through
said feed conduit during the delivery strokes of said piston
the next delivery stroke of piston l. Therefore, the pump
has a self-regulating operation.
This regulation effect may be combined with that
due to a variation of the cross sectional area of passage
both comprise a slide valve extending across said feed
conduit so as to be able either to close or to open it,
means, operatively connected with said mechanical means,
3 which may be obtained, as above stated, by a governor 35 for mechanically actuating said slide valve in one single
direction to close it at the beginning of every delivery
stroke of said piston and to keep it closed until the end
According to a second embodiment illustrated by FIG.
of said stroke, resilient means operatively connected with
3, passage 3 is arranged in such manner as to delay the
said slide valve for actuating said slide valve in the op
beginning of the return movement of piston 1 with re
posed direction, and means operatively connected with
spect to the time when sliding member l1 ceases to act
said slide valve for braking the movements thereof in
thereon through push-rod 9.
said last mentioned direction.
For this purpose, passage 3 is obtained by the coopera~
3. A pump according to claim 1 in which said means
tion with conduit 14 of the groove 25a of a slide valve 25
for delaying the flow of liquid through said feed conduit
actuated in one direction on every delivery stroke of pis
are means for throttling a portion of said last mentioned
ton 1 against the action of return means constituted for
conduit.
instance by a spring 7.6, the return movement of slide
4. A pump according to claim 1 in which said means
valve 25 under the action of said Spring 26 being braked
for preventing back flow of liquid through said feed con
by the fact that said slide valve drives out liquid to the
duit during the delivery strokes of said piston consist of a
outside through a throttled passage 27.
valve mounted in said feed conduit and hydraulically
To operate slide valve 25, shaft 8 carries a second cam
connected with said pressure chamber to be closed dur
28 cooperating with a push-rod 29 in contact with slide
ing the delivery strokes of said piston.
valve 25. The liquid which serves to brake the return
5. A pump according to claim 1 in which said means
movement of slide valve 25 is introduced through a con
for preventing back flow of liquid through said feed con
duit 3l into a cylinder 30 under a piston 32 rigid with
responsive to Variations of the speed of the engine.
slide valves 25, this liquid being driven out by this piston
duit during the delivery strokes of said piston consist of
through a conduit 33 including the above mentioned
throttled passage ‘27.
The general operation of the pump of FIG. 3 is similar
to that of the pumps of FIGS. 1 and 2. However, the
beginning of the downward movement of piston 1 instead 60
for delaying the flow of liquid through said feed conduit
of taking place when sliding member lll starts moving
downwardly (as in the case of FIGS. l and 2) takes
place only when the groove 25„ of slide valve 25 begins
to open conduit i142.
ln a general manner, while l have, in the above descrip
tion, disclosed what I deem to be practical and efficient
embodiment of my invention, it should be well under
a check valve mounted in said feed conduit.
6. A pump according to claim l in which the means
comprise a valve located in said feed conduit so as to be
`able either to close or to open it, means operatively con~
nected with said mechanical means for having said last
mentioned valve in feed conduit closing position at the
end of every delivery stroke of said piston and means
operatively connected with said last mentioned valve for
ringing it into feed conduit opening position some time
after the beginning of every return stroke of said piston.
7. A pump according to claim l in which the means
for delaying the ilow of liquid through said feed conduit
stood that l do not wish to be limited thereto as there
comprise a valve located in said feed conduit so as to be
might be changes made in the arrangement, disposition
and form of the parts without departing from the principle 70 able either to close or to open it, mechanical means op
eratively connected with said iirst mentioned mechanical
of the present invention as comprehended within the
means for acting in a single direction on said last men
scope of the accompanying claims.
What l claim is:
l. A self-regulating liquid pump which comprises, in
combination, a cylinder, a piston fitting slidably in said
tioned valve to have it closed at the end of every delivery
stroke of said piston while leaving said last mentioned
valve free to open at the beginning of every return stroke
‘i’
J
6
of said piston, resilient means operatively connected with
said last mentioned valve for urging it toward feed conduit opening position, and means operatively connected
with said last mentioned valve for braking the movement thereof toward feed conduit opening position.
5
2,066,673
2,243,117
2,281,045
2,720,842
2,940,398
References Cited in the file of this patent
UNITED STATES PATENTS
1,784,706
Dillstrom ____________ _... Jan. 5,
Patterson _____________,_ May 27,
`Outin _______________ __ Apr. 28,
Downing _____________ __.. Oct. 18,
Bessiere _____________ __ June 14,
1937
1941
1942
1955
1960
FOREIGN PATENTS
‘
Phillips ______________ __ Dec. 9, 1930 10
210,886
Great Britain _________ __ Feb. 11, 1924
457,966
Greatßritain __________ __ 1366.9,1936